Effects of low-to-high doses of aspirin on platelet aggregability and metabolites of thromboxane A2 and prostacyclin

Low dose aspirin and clinical outcomes in patients with SARS-CoV-2 pneumonia: a propensity score-matched cohort analysis from the National SIMI‑COVID‑19 Registry

BACKGROUND

SARS- CoV-2 virus has had dramatic consequences worldwide being able to cause acute respiratory distress syndrome (ARDS), massive thrombosis and pulmonary embolism and, finally, patients' death. In COVID-19 infection, platelets have a procoagulant phenotype that can cause thrombosis in the pulmonary and systemic vascular network. Aspirin is a well-known anti-platelet drug widely used for the prevention of cardiovascular events and systematic reviews suggest a possible benefit of low-dose aspirin (LDA) use in the prevention and treatment of ARDS in patients with COVID-19 infection. However, several studies are available in the literature which do not support any benefits and no association with the patients' outcome. Therefore, currently available data are inconclusive.

MATERIALS AND PATIENTS

Data from the nationwide cohort multicenter study of the Italian Society of Internal Medicine (SIMI) were analyzed. We conducted a propensity score-matched cohort analysis to investigate the impact of chronic assumption of LDA on mortality of adult COVID-19 patients admitted in Internal Medicine Units (IMU). Data from 3044 COVID-19 patients who referred to 41 Italian hospitals between February 3rd to May 8th 2020 were analyzed. A propensity score-matched analysis was conducted using the following variables: age, sex, hypertension, hyperlipidemia diabetes, atrial fibrillation, cerebrovascular disease, COPD, CKD and stratified upon LDA usage, excluding anticoagulant treatment. After matching, 380 patients were included in the final analysis (190 in LDA group and 190 in no-LDA group).

RESULTS

66.2% were male, median age was 77 [70-83]. 34.8% of the population died during the hospitalization. Cardiovascular diseases were not significantly different between the groups. After comparison of LDA and no-LDA subgroups, we didn't record a significant difference in mortality rate (35.7% vs 33.7%) duration of hospital stay and ICU admission. In a logistic regression model, age (OR 1.05; 95% CI 1.01-1.09), FiO2 (OR 1.024; 95% CI 1.03-1.04) and days between symptoms onset and hospitalization (OR 0.93; 95% CI 0.87-0.99) were the only variables independently associated with death.

Anti-Inflammatory Drug Therapy in Aneurysmal Subarachnoid Hemorrhage: A Systematic Review and Meta-Analysis of Prospective Randomized and Placebo-Controlled Trials

Emerging evidence suggests that neuroinflammation may play a potential role in aneurysmal subarachnoid hemorrhage (aSAH). We aim to analyze the influence of anti-inflammatory therapy on survival and outcome in aSAH. Eligible randomized placebo-controlled prospective trials (RCTs) were searched in PubMed until March 2023. After screening the available studies for inclusion and exclusion criteria, we strictly extracted the main outcome measures. Dichotomous data were determined and extracted by odds ratio (OR) with 95% confidence intervals (CIs). Neurological outcome was graded using the modified Rankin Scale (mRS). We created funnel plots to analyze publication bias. From 967 articles identified during the initial screening, we included 14 RCTs in our meta-analysis. Our results illustrate that anti-inflammatory therapy yields an equivalent probability of survival compared to placebo or conventional management (OR: 0.81, 95% CI: 0.55-1.19, p = 0.28). Generally, anti-inflammatory therapy trended to be associated with a better neurologic outcome (mRS ≤ 2) compared to placebo or conventional treatment (OR: 1.48, 95% CI: 0.95-2.32, p = 0.08). Our meta-analysis showed no increased mortality form anti-inflammatory therapy. Anti-inflammatory therapy in aSAH patients tends to improve the neurological outcome. However, multicenter, rigorous, designed, prospective randomized studies are still needed to investigate the effect of fighting inflammation in improving neurological functioning after aSAH.

Clinical pharmacology of antiplatelet drugs

INTRODUCTION

Platelets play a key role in arterial thrombosis and antiplatelet therapy is pivotal in the treatment of cardiovascular disease. Current antiplatelet drugs target different pathways of platelet activation and show specific pharmacodynamic and pharmacokinetic characteristics, implicating clinically relevant drug-drug interactions.

AREAS COVERED

This article reviews the role of platelets in hemostasis and cardiovascular thrombosis, and discusses the key pharmacodynamics, drug-drug interactions and reversal strategies of clinically used antiplatelet drugs.

EXPERT OPINION

Antiplatelet therapies target distinct pathways of platelet activation: thromboxane A₂ synthesis, adenosine diphosphate-mediated signaling, integrin α_IIbβ₃ (GPIIb/IIIa), thrombin-mediated platelet activation via the PAR1 receptor and phosphodiesterases. Key clinical drug-drug interactions of antiplatelet agents involve acetylsalicylic acid - ibuprofen, clopidogrel - omeprazole, and morphine - oral P2Y₁₂ inhibitors, all of which lead to an attenuated antiplatelet effect. Platelet function and genetic testing and the use of scores (ARC-HBR, PRECISE-DAPT, ESC ischemic risk definition) may contribute to a more tailored antiplatelet therapy. High on-treatment platelet reactivity presents a key problem in the acute management of ST-elevation myocardial infarction (STEMI). A treatment strategy involving early initiation of an intravenous antiplatelet agent may be able to bridge the gap of insufficient platelet inhibition in high ischemic risk patients with STEMI.

Comparison of Different Laboratory Tests to Identify “Aspirin Resistance” and Risk of Vascular Events among Ischaemic Stroke Patients: A Double-Blind Study

“Aspirin resistance” (AR) is associated with increased risk of vascular events. We aimed to compare different platelet function tests used in identifying AR and assess their implications on clinical outcome. We performed platelet aggregation studies on non-cardioembolic ischaemic stroke patients taking aspirin 100 mg/day and 30 non-stroke controls. Data were collected on demographics, vascular risk factors, and concomitant medications. Cut-offs for AR were (1) light transmission aggregometry (LTA) of ≥20% using arachidonic acid (AA), ≥70% using ADP, or ≥60% using collagen; and (2) VerifyNow® assay ≥ 550 ARU. Telephone follow-ups were conducted by study staff blinded to AR status to ascertain the occurrence of vascular outcomes (stroke, myocardial infarction, amputation, death). A total of 113 patients were recruited, mean age 65 ± 8 years, 47% women, 45 ± 15 days from index stroke. 50 (44.3%, 95% CI 34.9–53.9) had AR on at least 1 test. Frequency of AR varied from 0% to 39% depending on method used and first vs. recurrent stroke. There were strong correlations between LTA AA, VerifyNow® and Multiplate® ASPItest (r = 0.7457–0.8893), but fair to poor correlation between LTA collagen and Multiplate® COLtest (r = 0.5887) and between LTA ADP and Multiplate® ADPtest (r = 0.0899). Of 103 patients with a mean follow up of 801 ± 249 days, 10 (9.7%) had vascular outcomes, of which six had AR by LTA-ADP. AR by LTA-ADP is associated with increased risk of vascular outcome (p = 0.034). Identification of AR is not consistent across different platelet function tests. LTA of ≥70% using 10 µM ADP in post-stroke patients taking aspirin is associated with increased risk of vascular outcome.

Low-Dose Aspirin is Safe and Effective for Venous Thromboembolism Prevention in Patients Undergoing Revision Total Knee Arthroplasty: A Retrospective Cohort Study

Venous thromboembolism (VTE) events are rare, but serious complications of total joint replacement affect patients and health care systems due to the morbidity, mortality, and associated cost of its complications. There is currently no established universal standard of care for prophylaxis against VTE in patients undergoing revision total knee arthroplasty (rTKA). The aim of this study was to determine whether a protocol of 81-mg aspirin (ASA) bis in die (BID) is safe and/or sufficient in preventing VTE in patients undergoing rTKAs versus 325-mg ASA BID. In 2017, our institution adopted a new protocol for VTE prophylaxis for arthroplasty patients. Patients initially received 325-mg ASA BID for 1 month and then changed to a lower dose of 81-mg BID. A retrospective review from 2011 to 2019 was conducted identifying 1,438 consecutive rTKA patients and 90-day postoperative outcomes including VTE, gastrointestinal, and wound bleeding complications, acute periprosthetic joint infection, and mortality. In the 74 months prior to protocol implementation, 1,003 rTKAs were performed and nine VTE cases were diagnosed (0.90%). After 26 months of the protocol change, 435 rTKAs were performed with one VTE case identified (0.23%). There was no significant difference in rates or odds in postoperative pulmonary embolism (PE; p = 0.27), DVT (p = 0.35), and total VTE rates (p = 0.16) among patients using either protocol. There were also no differences in bleeding complications (p = 0.15) or infection rate (p = 0.36). No mortalities were observed. In the conclusion, 81-mg ASA BID is noninferior to 325-mg ASA BID in maintaining low rates of VTE and may be safe for use in patients undergoing rTKA.

Angina due to coronary artery spasm (variant angina): diagnosis and intervention strategies

INTRODUCTION

Since Prinzmetal first described a 'variant' form of angina pectoris, with predominantly resting episodes of pain and cyclic severity variations, it has gradually become apparent that this clinical presentation is caused by episodes of coronary artery spasm (CAS) involving focal or diffuse changes in large and/or small coronary arteries in the presence or absence of 'fixed' coronary artery stenoses. However, most clinicians have only limited understanding of this group of disorders.

AREAS COVERED

We examine the clinical presentation of CAS, associated pathologies outside the coronary vasculature, impediments to making the diagnosis, provocative diagnostic tests, available and emerging treatments, and the current understanding of pathogenesis.

EXPERT OPINION

CAS is often debilitating and substantially under-diagnosed and occur mainly in women. Many patients presenting with CAS crises have non-diagnostic ECGs and normal serum troponin concentrations, but CAS can be suspected on the basis of history and association with migraine, Raynaud's phenomenon and Kounis syndrome. Definitive diagnosis requires provocative testing at coronary angiography. Treatment still centers around the use of calcium antagonists, but with greater understanding of pathogenesis, new management options are emerging.

The effect of acetylsalicylic acid on pain and recurrence of endometriosis after surgery: A randomized controlled trial

Background:

Reactive oxygen species (ROS) might increase growth and adhesion of endometrial cells in the peritoneal cavity, and lead to endometriosis. In this study the we evaluate the effect of an antioxidant, acetylsalicylic acid (aspirin), to determine whether aspirin administration to patients with endometriosis would affect pelvic pain and disease recurrence.

Material and methods:

This randomized controlled trial was conducted from March 2018 to March 2020 on women, 19 to 40 years of age, who were diagnosed with endometriosis after undergoing laparoscopic surgery. Study participants were randomly assigned to one of two groups, Oral contraceptive pills (OCP) and placebo or OCP and aspirin, which were administered daily for 6 months. Pelvic pain, dysmenorrhea, mass size, and menstrual bleeding were evaluated at 3 and 6 months.

Results:

There were 38 patients in the aspirin group and 49 participants in the placebo group. The mean dysmenorrhea Visual analog scale (VAS) score after 3 months was 2.24 in the aspirin group and 3.61 in the placebo group. After 6 months, the dysmenorrhea VAS scores were 0.68 (aspirin group) and 2.69 (placebo group) ( p = 0.005 and p = 0.00, respectively). Dyspareunia and pelvic pain showed significant reductions ( p = 0.00). Six patients in the control group and four patients in the aspirin group experienced lesion recurrence ( p = 0.45).

Conclusion:

The results suggest that aspirin, as an antioxidant, could effectively reduce pain in women with endometriosis. However, additional studies that enroll larger numbers of participants and long-term follow up will enable better evaluation of recurrence.

Low-Dose Aspirin Is Safe and Effective for Venous Thromboembolism Prevention in Patients Undergoing Revision Total Hip Arthroplasty: A Retrospective Cohort Study

BACKGROUND

Currently, there is no established universal standard of care for prophylaxis against venous thromboembolism (VTE) in orthopedic patients undergoing revision total hip arthroplasty (rTHA). The aim of this study is to determine whether a protocol of 81-mg aspirin (ASA) bis in die (BID) is safe and/or effective in preventing VTE in patients undergoing rTHAs vs 325-mg ASA BID.

METHODS

In 2017, a large academic medical center adopted a new protocol for VTE prophylaxis in arthroplasty patients at standard risk. Initially, patients received 325-mg ASA BID but switched to 81-mg ASA BID. A retrospective review (2011-2019) was performed to identify 1361 consecutive rTHA patients and their associated 90-day postoperative complications such as VTE, including pulmonary embolism (PE) and/or deep vein thrombosis (DVT), as the primary outcome; and gastrointestinal and wound bleeding, acute periprosthetic joint infection, and mortality as the secondary outcome.

RESULTS

From 2011 to 2017, 973 rTHAs were performed and 13 total VTE cases were diagnosed (1.34%). From 2017 to 2019, 388 rTHAs were performed with 3 total VTE cases identified (0.77%). Chi-squared analyses and logistic regression models showed no differences in rates or odds in postoperative PE (P = .09), DVT (P = .79), PE and DVT (P = .85), and total VTE (P = .38) using either dose. There were also no differences between bleeding complications (P = .14), infection rate (P = .46), and mortality (P = .53).

CONCLUSION

Using a protocol of 81-mg of ASA BID is noninferior to 325-mg ASA BID and may be safe and effective in maintaining low rates of VTE in patients undergoing rTHA.

Effects of maternal aspirin treatment on hemodynamically significant patent ductus arteriosus in preterm infants - pilot study

Aim: To assess the burden of hemodynamically significant patent ductus arteriosus (hs-PDA) in preterm infants exposed to aspirin in utero.Methods: We retrospectively reviewed the medical records of 21 preterm infants <34 weeks whose mothers were treated with aspirin during gestation, and were screened for patent ductus arteriosus due to severe respiratory distress syndrome and the need for positive pressure ventilation. These infants were compared to 42 preterm infants born without exposure to aspirin in utero.Results: We found significantly lower frequency of hs-PDA and higher rate of successful pharmacological PDA closure after single course of ibuprofen treatment along with significantly lower cumulative doses of ibuprofen in the study group. Furthermore, PDA closure was achieved significantly earlier in the study group (day 4 versus 11, p = .02).Conclusion: Aspirin treatment during pregnancy seemed to reduce the incidence of hs-PDA in preterm infant and to increase infant responsiveness to postnatal medical treatment of PDA.

Novel approaches to P2Y12 inhibition and aspirin dosing

Aspirin and P2Y₁₂ inhibitors remain commonly prescribed antiplatelet drugs in the treatment of atherothrombotic conditions. Despite established benefits of dual antiplatelet therapy (DAPT) in the setting of acute coronary syndromes, there remains residual ischemic risk in this group and the problem of bleeding complications is an ongoing issue. DAPT with aspirin and ticagrelor has now been studied in other patient groups such as those with concurrent diabetes and stable coronary artery disease, and those undergoing elective percutaneous coronary intervention (PCI). Recent trials of ticagrelor monotherapy have suggested this may have benefits over standard-of-care in some settings, such as PCI, but not in others such as peripheral arterial disease or stroke. A novel subcutaneously administered P2Y₁₂ inhibitor, selatogrel, has shown powerful, rapid and consistent effect in a phase 2 study. Aspirin dosing remains an area of investigation, particularly in the setting of DAPT. A novel regimen of very-low-dose twice-daily aspirin has hypothetical advantages in pharmacodynamic and pharmacokinetic effects, maintaining antiplatelet effect whilst reducing potentially harmful peak-trough variation.

Endotoxin-induced changes in expression of cyclooxygenase isoforms in the lamellar tissue of extracorporeally haemoperfused equine limbs

Angiogenesis and sepsis‐related equine laminitis have several features in common. Both events can be induced by endotoxin (lipopolysaccharide— LPS) and both are associated with increased expression of the enzyme cyclooxygenase (COX), of which two isoforms (COX‐1 and COX‐2) exist. To examine the causal relationship between LPS exposure and COX expression and to investigate the tissue distribution of COX in the LPS‐exposed tissue, the technique of extracorporeal haemoperfusion of isolated equine forelimbs was utilized. Perfusion was performed for 10 hr under physiological conditions (control‐perfused limbs, n = 5) and with addition of 80 ng/L of endotoxin (LPS‐perfused limbs; n = 5). After perfusion, samples of lamellar tissue were collected from the dorsal aspect of the hoof wall. Additional control samples were collected from three non‐perfused limbs. Immunohistochemical analysis was performed using antibodies against COX‐1 and COX‐2, and intensity of immunohistochemical staining was scored for each isoform. In the lamellar tissue of control‐ and LPS‐perfused limbs, there was no significant difference in COX‐1 staining intensity and distribution, whereas COX‐2 expression was significantly increased in LPS‐perfused limbs (especially in endothelial cells, fibroblasts and intravasal leucocytes as well as in epidermal basal cells at the base of the primary epidermal lamellae). These results suggest that COX‐2 and its metabolites are involved in the initiation of pathological changes seen in sepsis‐associated events such as sepsis‐related laminitis. In such cases, COX‐2 could therefore be an important therapeutic target; however, early therapy may be required as increase in COX‐2 expression occurs within 10 hr after LPS exposure.

Blood transcriptomic biomarker as a surrogate of ischemic brain gene expression

Objectives

Blood biomarkers for cerebral tissue ischemia are lacking. The goal was to identify a blood transcriptomic signature jointly identified in the ischemic brain.

Methods

A nonhuman primate model with middle cerebral artery (MCA) territory infarction was used to study gene expression by microarray during acute ischemic cerebral stroke in the brain and the blood. Brain samples were collected in the infarcted and contralateral non‐infarcted cortex as well as blood samples before and after occlusion. Gene expression was compared between the two brain locations to find differentially expressed genes. The expressions of these genes were then compared in the blood pre‐ and post‐occlusion.

Results

Hierarchical clustering of brain expression data revealed strong independent clustering of ischemic and nonischemic brain samples. The top five enriched, up‐regulated gene sets in the brain were TNF α signaling, apoptosis, P53 pathway, hypoxia, and UV response up. A comparison of differentially expressed genes in the brain and blood revealed a significant overlap of gene expression patterns. Stringent analysis of blood expression data from pre‐ and post‐occlusion samples in each monkey identified nine genes highly differentially expressed in both the brain and the blood. Many of these up‐regulated genes belong to pathways involved in cell death and DNA damage repair.

Interpretation

Common gene expression profile can be identified in the brain and blood and clearly differentiates ischemic from nonischemic conditions. Therefore, specific blood transcriptomic signature may represent a surrogate for brain ischemic gene expression.

Circadian Rhythm of Cardiovascular Disease: The Potential of Chronotherapy With Aspirin

Almost all the systems in our body adhere to a daily 24 h rhythm. The cardiovascular system is also affected by this 24 h rhythm. In the morning there is a change in various cardiovascular processes, including platelet aggregability. These changes may play a role in the relative excess of early morning cardiovascular events. The number of recurrent cardiovascular diseases (CVD) could, in theory, be reduced by responding to this 24 h rhythm with timed medication intake (chronotherapy), which also applies to aspirin. Multiple studies on chronotherapy with low-dose aspirin are promising, showing a decrease in early morning platelet activity with evening intake compared with morning intake. However, in order to further demonstrate its clinical impact, randomized trials with cardiovascular events as a primary outcome are needed. This review discusses the available evidence of the effects of circadian rhythm on CVD and the potential positive effect of chronotherapy with aspirin.

Overcoming the Bitter Taste of Oils Enriched in Fatty Acids to Obtain Their Effects on the Heart in Health and Disease

Fatty acids come in a variety of structures and, because of this, create a variety of functions for these lipids. Some fatty acids have a role to play in energy metabolism, some help in lipid storage, cell structure, the physical state of the lipid, and even in food stability. Fatty acid metabolism plays a particularly important role in meeting the energy demands of the heart. It is the primary source of myocardial energy in control conditions. Its role changes dramatically in disease states in the heart, but the pathologic role these fatty acids play depends upon the type of cardiovascular disease and the type of fatty acid. However, no matter how good a food is for one's health, its taste will ultimately become a deciding factor in its influence on human health. No food will provide health benefits if it is not ingested. This review discusses the taste characteristics of culinary oils that contain fatty acids and how these fatty acids affect the performance of the heart during healthy and diseased conditions. The contrasting contributions that different fatty acid molecules have in either promoting cardiac pathologies or protecting the heart from cardiovascular disease is also highlighted in this article.

Very-low-dose twice-daily aspirin maintains platelet inhibition and improves haemostasis during dual-antiplatelet therapy for acute coronary syndrome

Higher aspirin doses may be inferior in ticagrelor-treated acute coronary syndrome (ACS) patients and reducing bleeding risk whilst maintaining antithrombotic benefits could improve outcomes. We characterized the pharmacodynamics of a novel dual-antiplatelet-therapy regimen consisting of very-low-dose twice-daily (BD) aspirin with standard-dose ticagrelor. A total of 20 ticagrelor-treated ACS patients entered a randomized crossover to take aspirin 20 mg BD (12-hourly) during one 14-day period and 75 mg once-daily (OD) in the other. After 14 days of treatment, serum thromboxane (TX)B2 and light-transmittance aggregometry were assessed pre- and 2 h post-morning-dose, bleeding time was measured post-dose, and TXA2 and prostacyclin stable metabolites were measured in urine collected 2 h post-morning-dose. Data are expressed as mean ± SD. After 14 days treatment, serum TXB2 levels were significantly greater 2 h post-dosing with aspirin 20 mg BD vs. 75 mg OD (3.0 ± 3.6 ng/mL vs. 0.8 ± 1.9 ng/mL; p = 0.018) whereas pre-dosing levels were not significantly different (3.5 ± 4.1 ng/mL vs. 2.5 ± 3.1 ng/mL, p = 0.23). 1-mmol/L arachidonic acid-induced platelet aggregation was similarly inhibited by both regimens pre-dose (8.5 ± 14.3% vs. 5.1 ± 3.6%, p = 0.24) and post-dose (8.7 ± 14.2% vs. 6.6 ± 5.3%; p = 0.41). Post-dose bleeding time was shorter with 20 mg BD (680 ± 306 s vs. 834 ± 386 s, p = 0.02). Urinary prostacyclin and TX metabolite excretion were not significantly different. In conclusion, compared to aspirin 75 mg OD, aspirin 20 mg BD provided consistent inhibition of platelet TXA2 release and aggregation, and improved post-dose hemostasis, in ticagrelor-treated ACS patients. Further studies are warranted to assess whether this regimen improves the balance of clinical efficacy and safety.

The prothrombotic state in atrial fibrillation: pathophysiological and management implications

Atrial fibrillation (AF) is the commonest sustained cardiac arrhythmia and is associated with significant morbidity and mortality. There is plenty of evidence available to support the presence of a prothrombotic or hypercoagulable state in AF, but the contributory factors are multifactorial and cannot simply be explained by blood stasis. Abnormal changes in atrial wall (anatomical and structural, as ‘vessel wall abnormalities’), the presence of spontaneous echo contrast to signify abnormal changes in flow and stasis (‘flow abnormalities’), and abnormal changes in coagulation, platelet, and other pathophysiologic pathways (‘abnormalities of blood constituents’) are well documented in AF. The presence of these components therefore fulfils Virchow’s triad for thrombogenesis. In this review, we present an overview of the established and professed pathophysiological mechanisms for thrombogenesis in AF and its management implications.

Effects of high- and low-dose aspirin on adaptive immunity and hypertension in the stroke-prone spontaneously hypertensive rat

Despite its well-known antithrombotic properties, the effect of aspirin on blood pressure (BP) and hypertension pathology is unclear. The hugely varying doses used clinically have contributed to this confusion, with high-dose aspirin still commonly used due to concerns about the efficacy of low-dose aspirin. Because prostaglandins have been shown to both promote and inhibit T-cell activation, we also explored the immunomodulatory properties of aspirin in hypertension. Although the common preclinical high dose of 100 mg/kg/d improved vascular dysfunction and cardiac hypertrophy, this effect was accompanied by indices of elevated adaptive immunity, renal T-cell infiltration, renal fibrosis, and BP elevation in stroke-prone spontaneously hypertensive rats and in angiotensin II-induced hypertensive mice. The cardioprotective effects of aspirin were conserved with a lower dose (10 mg/kg/d) while circumventing heightened adaptive immunity and elevated BP. We also show that low-dose aspirin improves renal fibrosis. Differential inhibition of the COX-2 isoform may underlie the disparate effects of the 2 doses. Our results demonstrate the efficacy of low-dose aspirin in treating a vast array of cardiovascular parameters and suggest modulation of adaptive immunity as a novel mechanism underlying adverse cardiovascular profiles associated with COX-2 inhibitors. Clinical studies should identify the dose of aspirin that achieves maximal cardioprotection with a new awareness that higher doses of aspirin could trigger undesired autoimmunity in hypertensive individuals. This work also warrants an evaluation of high-dose aspirin and COX-2 inhibitor therapy in sufferers of inflammatory conditions who are already at increased risk for cardiovascular disease.-Khan, S. I., Shihata, W. A., Andrews, K. L., Lee, M. K. S., Moore, X.-L., Jefferis, A.-M., Vinh, A., Gaspari, T., Dragoljevic, D., Jennings, G. L., Murphy, A. J., Chin-Dusting, J. P. F. Effects of high- and low-dose aspirin on adaptive immunity and hypertension in the stroke-prone spontaneously hypertensive rat.

Evidence based diagnosis and management of chronic subdural hematoma: A review of the literature

Chronic subdural hematomas are encapsulated blood collections within the dural border cells with characteristic outer "neomembranes". Affected patients are more often male and typically above the age of 70. Imaging shows crescentic layering of fluid in the subdural space on a non-contrast computed tomography (CT) scan, best appreciated on sagittal or coronal reformats. Initial medical management involves reversing anticoagulant/antiplatelet therapies, and often initiation of anti-epileptic drugs (AEDs). Operative interventions, such as twist-drill craniostomy (TDC), burr-hole craniostomy (BHC), and craniotomy are indicated if imaging implies compression (maximum fluid collection thickness >1 cm) or the patient is symptomatic. The effectiveness of various surgical techniques remains poorly characterized, with sparse level 1 evidence, variable outcome measures, and various surgical techniques. Postoperatively, subdural drains can decrease recurrence and sequential compression devices can decrease embolic complications, while measures such as early mobilization and re-initiation of anticoagulation need further study. Non-operative management, including steroid therapy, etizolam, tranexamic acid, and angiotensin converting enzyme inhibitors (ACEI) also remain poorly studied. Recurrent hemorrhages are a major complication affecting around 10-20% of patients, and therefore close follow-up is essential.

Management of the Pediatric Patient Following Upper Extremity Replantation or Revascularization: A Suggested Protocol

BACKGROUND

Traumatic pediatric amputations of the hand and upper extremity can have long-term financial, psychological, developmental, and functional consequences that readily extend beyond the realm of that which is normally encountered in comparatively injured adults. These factors, along with a paucity of medical comorbidities, have guided a more liberal and aggressive approach to treating pediatric amputations in hopes of optimizing psychosocial, aesthetic, and developmental outcomes. Furthermore, advances in pharmacology and microsurgical replantation techniques have allowed what were otherwise exceedingly rare surgeries to become commonplace in hospitals all over the world. Despite these gains, vascular thrombosis remains the leading cause of failure in microvascular surgeries. A recent survey showed that 96% of reconstructive surgeons use some form of anticoagulation therapy in their treatment, but no consensus regarding pharmacologic agents, dosing, or efficacy exists. The risk of thrombosis is further complicated by the dynamic nature of vasculature in response to stressors such as sympathetic tone, decreased intravascular volume, and response to external temperature. Given the lack of a higher-level evidence to guide the replantation surgeon in postoperative orders, we created an inclusive protocol, outlining complete and proper management of the pediatric patient following revascularization or replantation surgery.

METHODS

We reviewed the methods employed by our microvascular surgeons and consulted with board-certified pediatricians to produce a final document that was adopted ubiquitously among our providers.

RESULTS

We do not have head-to-head data demonstrating improved outcomes with use of the protocol. Nonetheless, the original document has been modified and reproduced here for your consideration and use.

CONCLUSIONS

Since initiating the protocol, we feel it has helped standardize our practice, avoid instances of incomplete or missed order sets, and facilitate interdisciplinary management through decreased gaps in communication, especially in those surgeries terminating in the middle of the night.

Safety of continuing aspirin therapy during spinal surgery: A systematic review and meta-analysis

BACKGROUND

Questions whether to continue or discontinue aspirin administration in the perioperative period of spinal surgery has not been systematically evaluated.

OBJECTIVE

The present systematic review is carried out to assess the impact of continuing aspirin administration on the bleeding and cardiovascular events in perispinal surgery period.

METHODS

Studies were retrieved through MEDLINE, EMBASE, and Springer Link Databases (search terms, aspirin, continue or discontinue, and spinal fusion), bibliographies of the articles retrieved, and the authors' reference files. We included studies that enrolled patients who underwent spinal surgery who were anticoagulated with aspirin alone and that reported bleeding or cardiovascular events as an outcome. Study quality was assessed using a validated form. 95% confidence interval (95% CI) was pooled to give summary estimates of bleeding and cardiovascular risk.

RESULTS

We identified 4 studies assessing bleeding risk associated with aspirin continuation or cardiovascular risk with aspirin discontinuation during spinal surgery. The continuation of aspirin will not increase the risk of blood loss during the spinal surgery (95% CI, -111.72 to -0.59; P = .05). Also, there was no observed increase in the operative time (95% CI, -33.29 to -3.89; P = .01) and postoperative blood transfusion (95% CI, 0.00-0.27; P = .05). But as for the cardiovascular risk without aspirin continuation and mean hospital length of stay with aspirin continuation, we did not get enough samples to make an accurate decision about their relations with aspirin.

CONCLUSION

Patients undergoing spinal surgery with continued aspirin administration do not have an increased risk for bleeding. In addition, there is no observed increase in the operation time and postoperative blood transfusion.

Dietary modulation of oxylipins in cardiovascular disease and aging

Oxylipins are a group of fatty acid metabolites generated via oxygenation of polyunsaturated fatty acids and are involved in processes such as inflammation, immunity, pain, vascular tone, and coagulation. As a result, oxylipins have been implicated in many conditions characterized by these processes, including cardiovascular disease and aging. The best characterized oxylipins in relation to cardiovascular disease are derived from the ω-6 fatty acid arachidonic acid. These oxylipins generally increase inflammation, hypertension, and platelet aggregation, although not universally. Similarly, oxylipins derived from the ω-6 fatty acid linoleic acid generally have more adverse than beneficial cardiovascular effects. Alternatively, most oxylipins derived from 20- and 22-carbon ω-3 fatty acids have anti-inflammatory, antiaggregatory, and vasodilatory effects that help explain the cardioprotective effects of these fatty acids. Much less is known regarding the oxylipins derived from the 18-carbon ω-3 fatty acid α-linolenic acid, but clinical trials with flaxseed supplementation have indicated that these oxylipins can have positive effects on blood pressure. Normal aging also is associated with changes in oxylipin levels in the brain, vasculature, and other tissues, indicating that oxylipin changes with aging may be involved in age-related changes in these tissues. A small number of trials in humans and animals with interventions that contain either 18-carbon or 20- and 22-carbon ω-3 fatty acids have indicated that dietary-induced changes in oxylipins may be beneficial in slowing the changes associated with normal aging. In summary, oxylipins are an important group of molecules amenable to dietary manipulation to target cardiovascular disease and age-related degeneration.NEW & NOTEWORTHY Oxylipins are an important group of fatty acid metabolites amenable to dietary manipulation. Because of the role they play in cardiovascular disease and in age-related degeneration, oxylipins are gaining recognition as viable targets for specific dietary interventions focused on manipulating oxylipin composition to control these biological processes.

Aspirin: The Mechanism of Action Revisited in the Context of Pregnancy Complications

Aspirin is one of the most frequently used and cheapest drugs in medicine. It belongs to the non-steroidal anti-inflammatory drugs with a wide range of pharmacological activities, including analgesic, antipyretic, and antiplatelet properties. Currently, it is accepted to prescribe a low dose of aspirin to pregnant women who are at high risk of preeclampsia (PE) because it reduces the onset of this complication. Another pregnancy alteration in which a low dose of aspirin is recommended is the obstetric antiphospholipid syndrome (APS). The most recognized mechanism of action of aspirin is to inhibit the synthesis of prostaglandins but this by itself does not explain the repertoire of anti-inflammatory effects of aspirin. Later, another mechanism was described: the induction of the production of aspirin-triggered lipoxins (ATLs) from arachidonic acid by acetylation of the enzyme cyclooxygenase-2. The availability of a stable analog of ATL has stimulated investigations on the use of this analog and it has been found that, similar to endogenously produced lipoxins, ATL resolves inflammation and acts as antioxidant and immunomodulator. If we consider that in PE and in the obstetric APS, there is an underlying inflammatory process, aspirin might be used based on the induction of ATL. The objective of this review is to revisit the old and new mechanisms of action of aspirin. In particular, it intends to show other potential uses of this drug to prevent certain pregnancy complications in the light of its ability to induce anti-inflammatory and pro-resolving lipid-derived mediators.

Acetylsalicylic acid supplementation improves protein utilization efficiency while vitamin E supplementation reduces markers of the inflammatory response in weaned pigs challenged with enterotoxigenic E. coli

Background

This experiment was conducted to test the hypothesis that vitamin E (Vit E) and acetylsalicylic acid (ASA), a cyclooxygenase-2 (COX-2) inhibitor, will additively reduce the production of the immunosuppressive molecule prostaglandin E₂ (PGE₂) and hence reduce inflammatory responses in weaner pigs experimentally infected with an enterotoxigenic strain of E. coli.

Methods

The experiment was conducted in a research facility with 192 individually-housed male weaner pigs (Landrace × Large White) weighing 6.6 ± 0.04 kg (mean ± SEM). The pigs were experimentally infected with an enterotoxigenic strain of E. coli and were allocated to a 2 × 3 factorial design with the respective factors being without and with 125 ppm ASA and three levels of Vit E supplementation (50, 100 or 200 IU/kg diet, dl-α-tocopheryl acetate).

Results

Acetylsalicylic acid supplementation improved average daily gain (P < 0.05) and tended to improve feed:gain ratio (P < 0.10) during the first 14 d after weaning. Acetylsalicylic acid supplementation also improved (P < 0.001) amino acid utilization efficiency (as assessed by plasma urea level) and tended to decrease (P < 0.10) PGE₂ production in the liver without affecting small intestinal histology and tight junction protein mRNA expression in the jejunal epithelium. Vitamin E supplementation greater than 100 IU/kg diet sustained both the plasma Vit E concentration (P < 0.001) and plasma haptoglobin content (P < 0.001) after weaning. However, there was no additive effects of the combined supplementation of ASA and Vit E on performance, intestinal barrier function and inflammatory responses of weaned pigs.

Conclusions

Although ASA and vitamin E improved amino acid utilization efficiency and reduced acute inflammatory responses, ASA and vitamin E did not additively reduce production of PGE₂ and inflammatory responses in weaner pigs experimentally infected with an enterotoxigenic strain of E. coli.

The Role of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) in the Treatment of Patients With Hepatic Disease: A Review Article

CONTEXT

Patients with hepatic dysfunction suffer from many problems and associated complications in organs other than the liver. Therefore, it is very important to investigate the effects of different drugs in the treatment of these patients. Due to the high consumption of non-steroidal anti-inflammatory drugs (NSAIDs), studying the effects of these drugs in patients with hepatic dysfunction is particularly important.

EVIDENCE ACQUISITION

Research studies published from 1958 to 2014 were investigated in the present study. The literature search was conducted based on the following keywords: non-steroidal anti-inflammatory drugs (NSAIDs), liver dysfunction, cirrhosis, pharmaceutical complications, drug-induced liver injury (DILI), and similar words from reliable resources. In total, 63 articles and two books (out of 179 initially identified resources) were included in the study.

RESULTS

In addition to significant hemostatic disorders and cardiovascular disorders, disorders of the renal, respiratory, and gastrointestinal systems, as well as disorders of the central nervous system, occur in patients with hepatic dysfunction. The various NSAIDs have different effects on different bodily systems. Therefore, the appropriate drug should be chosen based on both the condition of the disease and the severity of the dysfunction.

CONCLUSIONS

Due to the potential adverse effects of NSAIDs in patients with hepatic disease, their impact on all bodily systems should be emphasized when determining whether their use is necessary. Further, the appropriate medication should be selected after a careful assessment of the severity of the disease and any associated complications. It is logical that medicines should only be prescribed by a qualified physician.

Comparison of Cyclooxygenase Inhibition with Two Different Doses of Enteric Coated Aspirin in Normal Young and Elderly Subjects and Elderly with Cerebrovascular Disease

There is still controversy about the optimum dose and formulation of aspirin for prophylaxis of thrombo-embolic events in patients with cerebrovascular disease. Enteric coated formulations of aspirin have po tential advantages over rapidly absorbed formulations in terms of fewer side effects and more selective platelet cyclooxygenase inhibition. We compared 7-day courses of 100 mg and 650 mg per day enteric coated aspirin in young, healthy subjects and in two groups of elderly sub jects of 70 years and above, one group without vascular disease and the other with cerebrovascular disease. Prior to aspirin treatment, the elderly with cerebrovascular dis ease had higher levels of the urinary thromboxane A2 (TXA2) metabolite 11-dehydro-TXB2; the mean in the el derly ill was 4,064 ± 1,762 pg/mg creatinine (n = 8) com pared to levels of 982 ± 139 pg/mg creatinine (n = 17) in the young, and 1,560 ± 380 pg/mg creatinine (n = 14) in the healthy elderly (p < 0.05 and p < 0.01, respectively). Aspirin (100 mg) inhibited serum TXB2 generation in all groups, with the greatest percentage inhibition occurring in the elderly with cerebrovascular disease. In the ill el derly serum TXB2 was 1.9 ± 0.05% (n = 8) of control compared to 4.2 ± 0.6% (n = 17, p < 0.05) in the young and 9.4 ± 3.5% (n = 14, p < 0.01) in the healthy elderly. All young and diseased elderly subjects achieved greater than 90% inhibition with 100 mg aspirin, but 4 of 14 healthy elderly subjects achieved less than 90% inhibi tion. The 650-mg dose of aspirin produced further inhibi tion in serum TXB2 in the young and healthy elderly sub jects and inhibited serum TXB2 to greater than 90% of control levels in all subjects. The higher dose also pro duced greater reductions in 11-dehydro-TXB2 levels, and these were statistically significant in the young and ill elderly. Urinary-6-keto PGF1α was not significantly de creased at either dose, except in the elderly ill taking 650 mg a day in whom it was reduced to 55 ± 18% of control (n = 8, p < 0.05). Thus enteric coated aspirin at doses of 100 and 650 mg taken daily for 7 days inhibited platelet cyclooxygenase with relative sparing of endothelial cy clooxygenase. The elderly with cerebrovascular disease were more sensitive to the platelet and endothelial cyclo oxygenase inhibition effects of enteric coated aspirin than the healthy elderly and healthy young groups.

Aspirin Resistance

OBJECTIVE:

To review the literature addressing the problem of aspirin resistance in patients with vascular disease.

DATA SOURCES:

A MEDLINE search (1966–February 2002) was performed. Key search terms included aspirin, resistance, resistant, failure, tolerance, and nonresponder. English-language studies were identified as well as pertinent references from these articles.

DATA SYNTHESIS:

Aspirin resistance has been reported in patients with cardiovascular, cerebrovascular, and peripheral vascular disease. Because of differences in the definition of resistance, variations in detection methods, and a lack of controlled trials, the true significance of the problem remains unknown. Multiple mechanisms for resistance have been proposed, including increased reactivity to platelet aggregating factors, genetic polymorphism, and alternate pathways for thromboxane synthesis. The studies to date have failed to demonstrate consistent relationships between aspirin's platelet-inhibiting effects, the impact of dosage escalation, and clinical outcomes.

CONCLUSIONS:

For many patients, aspirin is an effective antithrombotic agent. However, patients taking aspirin may demonstrate highly variable responses to in vitro tests for platelet aggregation and may experience breakthrough thromboembolic events. Although this phenomenon has been termed aspirin resistance, the lack of a uniform definition or agreement on diagnostic criteria precludes definitive recommendations at this time. In addition, strategies are needed to identify patients at risk for aspirin resistance who might benefit from alternative or combined antiplatelet therapy.

How Resistant to Tampering are Codeine Containing Analgesics on the Market? Assessing the Potential for Opioid Extraction

Introduction

Misuse of opioid analgesics, in combination with diversion, dependence, and fatal overdoses, presents a serious problem for public health, which affects many countries worldwide. Within this context, tampering with opioids has been associated with serious harm. The aim of the present study was to assess the tampering potential of codeine combination analgesics on the market (containing codeine/non-opioid analgesics) by the extraction of codeine.

Methods

Codeine was extracted from three combination formulations sold lawfully from licensed pharmacies without a medical prescription in Denmark and the UK. Extraction of codeine followed tampering procedures available on the Internet. The amounts of codeine and accompanying non-opioid analgesics in tampering products were analysed with liquid chromatography and tandem mass spectrometry (LC–MS/MS).

Results

LC–MS/MS showed recoveries of the total amounts of codeine in tampering products of 81–84% from Product 1 (codeine/acetylsalicylic acid); 61–67% from Product 2 (codeine/ibuprofen); and 42–71% from Product 3 (codeine/paracetamol). Recoveries of non-opioid analgesics ranged between: 57–73% acetylsalicylic acid; 5.5–8.5% ibuprofen, and 5.0–9.2% paracetamol.

Conclusion

With the tampering procedures used, high amounts of codeine were separated from the accompanying analgesics in some, but not in all of the codeine containing formulations. Evidence-based medicine regulation, treatment for opioid dependence, and information to minimise risks to the public are essential components of an effective public health strategy to address the harms of tampering and misuse.

Funding

Marie Pedersen and Jensine Heiberg Foundation.

From plant extract to molecular panacea: a commentary on Stone (1763) 'An account of the success of the bark of the willow in the cure of the agues'

The application of aspirin-like drugs in modern medicine is very broad, encompassing the treatment of inflammation, pain and a variety of cardiovascular conditions. Although anecdotal accounts of willow bark extract as an anti-inflammatory drug have occurred since written records began (for example by Hippocrates), the first convincing demonstration of a potent anti-pyretic effect of willow bark containing salicylates was made by the English cleric Edward Stone in the late eighteenth century. Here, we discuss the route to optimizing and understanding the mechanism of action of anti-inflammatory drugs that have their origins in Stone's seminal study, ‘An account of the success of the bark of the willow in the cure of agues’. This commentary was written to celebrate the 350th anniversary of the journal Philosophical Transactions of the Royal Society.

Urinary 11-dehydro-thromboxane B2 is associated with cardiovascular events and mortality in patients with atrial fibrillation

BACKGROUND

Patients with nonvalvular atrial fibrillation (AF) show high residual cardiovascular (CV) risk despite oral anticoagulants. Urinary 11-dehydro-thromboxane B2 (TxB2) is associated with an increased risk of CV events (CVEs), but its predictive value in patients with anticoagulated AF is unknown.

METHODS

A prospective single-center cohort study, including 837 patients with AF, was conducted. Mean time of follow-up was 30.0 months, yielding 2,062 person-years of observation. Urinary 11-dehydro-TxB2 was measured at baseline. The primary end point was the occurrence of a CVE including fatal/nonfatal myocardial infarction and ischemic stroke, transient ischemic attack, cardiac revascularization, and CV death.

RESULTS

Mean age of patients was 73.1 years, and 43.6% were women. Median 11-dehydro-TxB2 levels were 100 (interquartile range 50-187) ng/mg of urinary creatinine. Overall, the anticoagulation control was adequate (63.9% of mean time in therapeutic range). A CVE occurred in 99 (11.8%) patients, and 55 were CV deaths. At baseline, 11-dehydro-TxB2 levels were higher in patients with a CVE compared with those without (186 [107-400] vs 98 [52-170], P < .001). An increased rate of CVEs (log-rank test, P < .001) and CV deaths (P < .001) was observed across tertiles of 11-dehydro-TxB2. Cardiovascular events were associated with age (hazard ratios [HR] 1.72 per 1 SD, 95% CI 1.33-2.21, P < .001), diabetes mellitus (HR 1.89, 95% CI 1.20-2.96, P = .005), heart failure (HR 1.60, 95% CI 1.01-2.54, P = .044), history of stroke/transient ischemic attack (HR 1.96, 95% CI 1.25-3.06, P = .003), and 11-dehydro-TxB2 (HR 1.64 per 1 SD, 95% CI 1.42-1.89, P < .001).

CONCLUSIONS

Urinary 11-dehydro-TxB2 levels are associated with a residual risk of CVEs and CV mortality in patients with AF despite anticoagulant treatment.

Urinary metabolites of prostanoids and risk of recurrent colorectal adenomas in the Aspirin/Folate Polyp Prevention Study (AFPPS)

Aspirin has been shown to protect against colorectal neoplasms; however, the optimal chemopreventive dose and underlying mechanisms are unclear. We aimed to study the relationship between prostanoid metabolites and aspirin's effect on adenoma occurrence. We used data from the Aspirin/Folate Polyp Prevention Study, in which 1,121 participants with a recent adenoma were randomized to placebo or two doses of aspirin (81 or 325 mg/d) to be taken until the next surveillance colonoscopy, anticipated about 3 years later. Urinary metabolites of prostanoids (PGE-M, PGI-M, and dTxB2) were measured using liquid chromatography/mass spectrometry or GC/NICI-MS in 876 participants near the end of treatment follow-up. Poisson regression with a robust error variance was used to calculate relative risks and 95% confidence intervals. PGE-M, PGI-M, and dTxB2 levels were 28%, 37%, and 60% proportionately lower, respectively, in individuals who took 325 mg of aspirin compared with individuals who took placebo (all P < 0.001). Similarly, among individuals who took 81 mg of aspirin, PGE-M, PGI-M, and dTxB2 were, respectively, 18%, 30%, and 57% proportionally lower compared with placebo (all P < 0.005). None of the metabolites or their ratios were statistically significantly associated with the risk of adenoma occurrence. The effect of aspirin in reducing adenoma risk was independent of prostanoid levels. Aspirin use is associated with lower levels of urinary prostanoid metabolites. However, our findings do not support the hypothesis that these metabolites are associated with adenoma occurrence, suggesting that COX-dependent mechanisms may not completely explain the chemopreventive effect of aspirin on colorectal neoplasms.

Baseline placental growth factor levels for the prediction of benefit from early aspirin prophylaxis for preeclampsia prevention

OBJECTIVE

Placental growth factor (PlGF) levels early in pregnancy are lower in women who ultimately develop preeclampsia. Early initiation of low-dose aspirin reduces preeclampsia risk in some high risk women. We hypothesized that low PlGF levels may identify women at increased risk for preeclampsia who would benefit from aspirin.

STUDY DESIGN

Secondary analysis of the MFMU High-Risk Aspirin study including singleton pregnancies randomized to aspirin 60mg/d (n=102) or placebo (n=72), with PlGF collected at 13w 0d-16w 6d. Within the placebo group, we estimated the probability of preeclampsia by PlGF level using logistic regression analysis, then determined a potential PlGF threshold for preeclampsia prediction using ROC analysis. We performed logistic regression modeling for potential confounders.

RESULTS

ROC analysis indicated 87.71pg/ml as the threshold between high and low PlGF for preeclampsia-prediction. Within the placebo group high PlGF weakly predicted preeclampsia (AUC 0.653, sensitivity/specificity 63%/66%). We noted a 2.6-fold reduction in preeclampsia with aspirin in the high-PlGF group (12.15% aspirin vs 32.14% placebo, p=0.057), but no significant differences in preeclampsia in the low PlGF group (21.74% vs 15.91%, p=0.445).

CONCLUSIONS

Unlike other studies, we found that high rather than low PlGF levels were associated with an increased preeclampsia risk. Low PlGF neither identified women at increased risk of preeclampsia nor women who benefitted from aspirin. Further research is needed to determine whether aspirin is beneficial in women with high PlGF, and whether the paradigm linking low PlGF and preeclampsia needs to be reevaluated.

CONDENSATION

High-risk women with low baseline PlGF, a risk factor for preeclampsia, did not benefit from early initiation of low-dose aspirin.

Early initiation of low-dose aspirin for reduction in preeclampsia risk in high-risk women: a secondary analysis of the MFMU High-Risk Aspirin Study

OBJECTIVE

Early initiation of low-dose aspirin (LDA) may reduce preeclampsia risk. We sought to determine whether LDA was beneficial when initiated <17w0d, within a trial of high-risk women enrolled <26w0d.

STUDY DESIGN

Secondary analysis of the Maternal-Fetal Medicine Units High-Risk Aspirin study, including women enrolled <17w0d, randomized to LDA (60 mg day(-1)) or placebo with chronic hypertension (CHTN, n=186), diabetes (n=191) or prior preeclampsia (n=146). The primary outcome was preeclampsia at any time in pregnancy, secondary outcomes were early preeclampsia (<34w0d), late preeclampsia (⩾34w), small for gestational age (SGA; neonatal birthweight <10th %) and composite (early preeclampsia or SGA). Outcomes were compared by exact Χ(2)-tests.

RESULTS

Baseline characteristics were similar between treatment groups. Aspirin was associated with a lower rate of late-onset preeclampsia ⩾34w (17.36% vs 24.42%, P=0.047), with a 41% reduction in women with CHTN (18.28% vs 31.18%, P=0.041). There were no other significant differences in the outcome.

CONCLUSION

Aspirin initiated <17w0d reduced the risk for late-onset preeclampsia by 29% supporting the practice of early initiation of aspirin in high-risk women.

Low-dose aspirin (acetylsalicylate) prevents increases in brain PGE2, 15-epi-lipoxin A4 and 8-isoprostane concentrations in 9 month-old HIV-1 transgenic rats, a model for HIV-1 associated neurocognitive disorders

BACKGROUND

Older human immunodeficiency virus (HIV)-1 transgenic rats are a model for HIV-1 associated neurocognitive disorders (HAND). They show behavioral changes, neuroinflammation, neuronal loss, and increased brain arachidonic acid (AA) enzymes. Aspirin (acetylsalicylate, ASA) inhibits AA oxidation by cyclooxygenase (COX)-1 and COX-2.

HYPOTHESIS

Chronic low-dose ASA will downregulate brain AA metabolism in HIV-1 transgenic rats.

METHODS

Nine month-old HIV-1 transgenic and wildtype rats were given 42 days of 10mg/kg/day ASA or nothing in drinking water; eicosanoids were measured using ELISAs on microwaved brain extracts.

RESULTS

Brain 15-epi-lipoxin A4 and 8-isoprostane concentrations were significantly higher in HIV-1 transgenic than wildtype rats; these differences were prevented by ASA. ASA reduced prostaglandin E2 and leukotriene B4 concentrations in HIV-1 Tg but not wildtype rats. Thromboxane B2, 15-HETE, lipoxin A4 and resolvin D1 concentrations were unaffected by genotype or treatment.

CONCLUSION

Chronic low-dose ASA reduces AA-metabolite markers of neuroinflammation and oxidative stress in a rat model for HAND.

Thrombin based gelatin matrix and fibrin sealant mediated clot formation in the presence of clopidogrel

BACKGROUND

Platelet inhibitors are commonly used to reduce the risk of atherothrombotic events. The aim of this study was to determine the impact of platelet inhibitors, specifically clopidogrel and aspirin, on clot kinetics, strength, and/or structure during the use of thrombin based gelatin matrices and fibrin sealants.

METHODS

Blood was collected and heparinized from donors on clopidogrel (and aspirin) and age matched control donors. Blood component analysis, whole blood platelet aggregometry, and activated clotting time (ACT) were used to monitor compliance to therapy and identify any differences between donor groups. Clot kinetics and strength were analyzed using thrombelastography (TEG). Field Emission Scanning Electron Microscopy (FESEM) was used to analyze clot structure.

RESULTS

Blood component profiles were similar for both donor groups. Aggregometry indicated that aggregation response to adenosine diphosphate (ADP) for clopidogrel donors was 12% of that for the controls (p = 0.0021), an expected result of clopidogrel induced platelet inhibition. However, blood from both donor groups had an elevated thrombin induced aggregation response. Heparinization of donor blood resulted in similarly elevated ACTs for both donor groups. TEG results indicated similar clot kinetics and strength between clopidogrel and control donor groups for blood alone and when clotting was induced using thrombin based gelatin matrices and fibrin sealants. FESEM images supported TEG findings in that similar morphologies were observed in ex vivo formed clots from both donor groups when thrombin based gelatin matrices and fibrin sealants were used.

CONCLUSION

These results suggest that platelet inhibitors do not negatively impact clot kinetics, strength, and structure when clotting is initiated with thrombin based gelatin matrices and fibrin sealants.

Tranexamic Acid Tamponade to Control Postoperative Surgical Hemorrhage

When preparing for oral surgery, patients taking anticoagulants usually should not discontinue their medication because of the risk of a thromboembolic event. The therapeutic effect of many anticoagulants is not readily measured, so preoperatively, the surgeon cannot know the true risk for postoperative hemorrhage. The risk of a thromboembolic event usually outweighs the concerns of controlling postoperative hemorrhage. Hemophilia patients are also at risk for postoperative bleeding. Single extractions probably do not pose a serious risk for postoperative hemorrhage. However, when a mucogingival flap is raised in these patients, there may be prolonged bleeding. Surgical sponges saturated with aqueous tranexamic acid solution and compressed onto the bleeding site with biting pressure may stop bleeding. Bleeding was stopped in the case example presented here after three 10-minute compressions over 30 minutes in a patient taking aspirin and clopidogrel for a previous thromboembolic event and a metal coronary stent. The clot formed is very fragile and is prone to bleeding, so it should not be disturbed. This technique needs to be studied for efficacy.

Safety of perioperative aspirin therapy in pancreatic operations

BACKGROUND

Antiplatelet therapy with aspirin is prevalent among patients presenting for operative treatment of pancreatic disorders. Operative practice has called for the cessation of aspirin 7-10 days before elective procedures because of the perceived increased risk of procedure-related bleeding. Our practice at Thomas Jefferson University has been to continue aspirin therapy throughout the perioperative period in patients undergoing elective pancreatic surgery.

STUDY DESIGN

Records for patients undergoing pancreatoduodenectomy, distal pancreatectomy, or total pancreatectomy between October 2005 and February 2012 were queried for perioperative aspirin use in this institutional research board-approved retrospective study. Statistical analyses were performed with Stata software.

RESULTS

During the study period, 1,017 patients underwent pancreatic resection, of whom 289 patients (28.4%) were maintained on aspirin through the morning of the operation. Patients in the aspirin group were older than those not taking aspirin (median 69 years vs 62 years, P < .0001). The estimated intraoperative blood loss was similar between the two groups, aspirin versus no aspirin (median 400 mL vs 400 mL, P = .661), as was the rate of blood transfusion anytime during the index admission (29% vs 26%, P = 0.37) and the postoperative duration of hospital stay (median 7 days vs 6 days, P = .103). The aspirin group had a slightly increased rate of cardiovascular complications (10.1% vs 7.0%, P = .107), likely reflecting their increased cardiovascular comorbidities that led to their physicians recommending aspirin therapy. Rates of pancreatic fistula (15.1% vs 13.5%, P = .490) and hospital readmissions were similar (16.9% vs 14.9%, P = .451).

CONCLUSION

This is the first study to report that aspirin therapy is not associated with increased rates of perioperative bleeding, transfusion requirement, or major procedure related complications after elective pancreatic surgery. These data suggest that continuation of aspirin is safe and that the continuation of aspirin should be considered acceptable and preferable, particularly in patients with perceived substantial medical need for treatment with antiplatelet therapy.

Confirmation of reported aspirin use in community studies: utility of serum thromboxane B2 measurement

Aspirin (ASA) is recommended for the prevention of cardiovascular disease; however, the compliance is low. Reported use may not reflect actual use. Serum thromboxane B2 (STxB2) measurement was evaluated to validate reported ASA use. Males aged 45 to 79 years and females aged 55 to 79 years completed a survey and STxB2 measurement (Thromboxane B2 EIA Kit; Cayman Chemical, Ann Arbor, Michigan). The 107 patients were grouped by use of ASA (56 ASA+ and 51 ASA-) and possible interfering medications (INT) such as nonsteroidal anti-inflammatory drugs. The STxB2 levels (ng/mL) were significantly lower in ASA users: ASA+ INT- 3.0 (0.7, 8.4), ASA+ INT+ 2.0 (0.8, 4.9), ASA- INT+ 176 (75, 390), and ASA- INT- 271 (199, 366). The INT use did not cause a significant difference in STxB2 levels. A STxB2 cut point of 25 ng/mL had high sensitivity (94.1%) and specificity (91.1%) for ASA use. The STxB2 was a reliable marker of ASA use and could be used to confirm ASA exposure in population-based health studies.

Aspirin and platelet adenosine diphosphate receptor antagonists in acute coronary syndromes and percutaneous coronary intervention: role in therapy and strategies to overcome resistance

Platelet activation and aggregation are key components in the cascade of events causing thrombosis following plaque rupture. Antiplatelet therapy is essential in the treatment of patients with acute coronary syndromes (ACS) and for those requiring percutaneous coronary intervention (PCI). Aspirin (acetylsalicylic acid) is a well established antiplatelet therapy and is mandated for secondary prevention of cardiovascular events following ACS. In patients with ACS, the addition of clopidogrel to aspirin is more effective than aspirin alone. For patients undergoing PCI, dual antiplatelet therapy with aspirin and clopidogrel is warranted. Aspirin should be continued indefinitely after PCI. Pretreatment of patients with clopidogrel prior to PCI lowers the incidence of cardiovascular events, yet the optimum timing of drug administration and dose are still being investigated, as is the duration of therapy following PCI. Late-stent thrombosis with drug-eluting stents has pushed the recommendation for duration of clopidogrel therapy up to 1 year and perhaps beyond, in patients without risks for bleeding. The concepts of aspirin and clopidogrel resistance are important clinical questions. No uniform definition exists for aspirin or clopidogrel resistance. Measurements of resistance are often highly variable and do not necessarily correlate with clinical resistance. Noncompliance remains the most prominent mode of resistance. Screening of selected patient populations for resistance or pharmacologic intervention of those patients termed 'resistant' warrants further study.

Evaluation of the pharmacodynamics of acetylsalicylic acid 81 mg with or without esomeprazole 20 mg in healthy volunteers

BACKGROUND

The absence of a pharmacokinetic interaction between the proton pump inhibitor esomeprazole (40 mg) and acetylsalicylic acid (aspirin, ASA; 325 mg) has previously been established.

OBJECTIVE

This study set out to investigate the potential for pharmacodynamic interaction between low-dose ASA and esomeprazole in healthy volunteers, by measuring ASA antiplatelet activity.

STUDY DESIGN

This was a single-center, open-label, two-period, randomized crossover study.

PARTICIPANTS

Healthy male and female volunteers aged 18-75 years were included. All volunteers received ASA 81 mg once daily for 5 days prior to the study (pre-screen). Subjects were eligible for inclusion if they had aspirin reactivity units (ARU, as measured by the VerifyNow ASA assay) of <550 on Day 6.

INTERVENTION

After pre-screening and a washout period of at least 14 days, eligible volunteers received ASA 81 mg with or without esomeprazole 20 mg once daily for 5 days in randomized order, with a 14-day washout between treatments.

MAIN OUTCOME MEASURE

The main outcome measure was the antiplatelet activity of ASA, as assessed by ARU ratio relative to baseline in the VerifyNow ASA assay; suppression of serum thromboxane B(2) (TXB(2)) was a secondary endpoint. Statistical comparisons were made using linear mixed models.

RESULTS

A total of 29 volunteers (19 aged ≥50 years; 8 women; 21 men) were evaluable for pharmacodynamic analysis (per protocol). All volunteers on both treatments achieved ARU <550 at Day 6. The geometric mean ratio of Day 6 to Day 1 (baseline) platelet aggregation was 0.70 (95% confidence interval [CI] 0.68, 0.72) with ASA alone and 0.71 (95% CI 0.69, 0.74) with ASA + esomeprazole. The ratio of platelet aggregation (ASA + esomeprazole/ASA) was 1.02 (95% CI 0.99, 1.05). ASA administered alone or with esomeprazole reduced serum TXB(2) by more than 99.5%. The ratio of suppression of serum TXB(2) levels (ASA + esomeprazole/ASA) was 1.06 (95% CI 0.88, 1.29). The combination of ASA and esomeprazole was well tolerated.

CONCLUSION

No pharmacodynamic interaction between low-dose ASA and esomeprazole was found with regard to platelet function.

TRIAL REGISTRATION

Registered at ClinicalTrials. gov as NCT01199328.

Multinational evidence-based recommendations for pain management by pharmacotherapy in inflammatory arthritis: integrating systematic literature research and expert opinion of a broad panel of rheumatologists in the 3e Initiative

OBJECTIVE

To develop evidence-based recommendations for pain management by pharmacotherapy in patients with inflammatory arthritis (IA).

METHODS

A total of 453 rheumatologists from 17 countries participated in the 2010 3e (Evidence, Expertise, Exchange) Initiative. Using a formal voting process, 89 rheumatologists representing all 17 countries selected 10 clinical questions regarding the use of pain medications in IA. Bibliographic fellows undertook a systematic literature review for each question, using MEDLINE, EMBASE, Cochrane CENTRAL and 2008-09 European League Against Rheumatism (EULAR)/ACR abstracts. Relevant studies were retrieved for data extraction and quality assessment. Rheumatologists from each country used this evidence to develop a set of national recommendations. Multinational recommendations were then formulated and assessed for agreement and the potential impact on clinical practice.

RESULTS

A total of 49,242 references were identified, from which 167 studies were included in the systematic reviews. One clinical question regarding different comorbidities was divided into two separate reviews, resulting in 11 recommendations in total. Oxford levels of evidence were applied to each recommendation. The recommendations related to the efficacy and safety of various analgesic medications, pain measurement scales and pain management in the pre-conception period, pregnancy and lactation. Finally, an algorithm for the pharmacological management of pain in IA was developed. Twenty per cent of rheumatologists reported that the algorithm would change their practice, and 75% felt the algorithm was in accordance with their current practice.

CONCLUSIONS

Eleven evidence-based recommendations on the management of pain by pharmacotherapy in IA were developed. They are supported by a large panel of rheumatologists from 17 countries, thus enhancing their utility in clinical practice.

Anti-platelet therapy: cyclo-oxygenase inhibition and the use of aspirin with particular regard to dual anti-platelet therapy

Aspirin and P2Y(12) antagonists are commonly used anti-platelet agents. Aspirin produces its effects through inhibition of thromboxane A(2) (TXA(2)) production, while P2Y(12) antagonists attenuate the secondary responses to ADP released by activated platelets. The anti-platelet effects of aspirin and a P2Y(12) antagonist are often considered to be separately additive. However, there is evidence of an overlap in effects, in that a high level of P2Y(12) receptor inhibition can blunt TXA(2) receptor signalling in platelets and reduce platelet production of TXA(2). Against this background, the addition of aspirin, particularly at higher doses, could cause significant reductions in the production of prostanoids in other tissues, e.g. prostaglandin I(2) from the blood vessel wall. This review summarizes the data from clinical studies in which dose-dependent effects of aspirin on prostanoid production have been evaluated by both plasma and urinary measures. It also addresses the biology underlying the cardiovascular effects of aspirin and its influences upon prostanoid production throughout the body. The review then considers whether, in the presence of newer, more refined P2Y(12) receptor antagonists, aspirin may offer less benefit than might have been predicted from earlier clinical trials using more variable P2Y(12) antagonists. The possibility is reflected upon, that when combined with a high level of P2Y(12) blockade the net effect of higher doses of aspirin could be removal of anti-thrombotic and vasodilating prostanoids and so a lessening of the anti-thrombotic effectiveness of the treatment.

Safety of non-steroidal anti-inflammatory drugs, including aspirin and paracetamol (acetaminophen) in people receiving methotrexate for inflammatory arthritis (rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, other spondyloarthritis)

BACKGROUND

Methotrexate is routinely used in the treatment of inflammatory arthritis. There have been concerns regarding the safety of using concurrent non-steroidal anti-inflammatory drugs (NSAIDs), including aspirin, or paracetamol (acetaminophen), or both, in these people.

OBJECTIVES

To systematically appraise and summarise the scientific evidence on the safety of using NSAIDs, including aspirin, or paracetamol, or both, with methotrexate in inflammatory arthritis; and to identify gaps in the current evidence, assess the implications of those gaps and to make recommendations for future research to address these deficiencies.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, second quarter 2010); MEDLINE (from 1950); EMBASE (from 1980); the Cochrane Database of Systematic Reviews (CDSR) and the Database of Abstracts of Reviews of Effects (DARE). We also handsearched the conference proceedings for the American College of Rheumatology (ACR) and European League against Rheumatism (EULAR) (2008 to 2009) and checked the websites of regulatory agencies for reported adverse events, labels and warnings.

SELECTION CRITERIA

Randomised controlled trials and non-randomised studies comparing the safety of methotrexate alone to methotrexate with concurrent NSAIDs, including aspirin, or paracetamol, or both, in people with inflammatory arthritis.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the search results, extracted data and assessed the risk of bias of the included studies.

MAIN RESULTS

Seventeen publications out of 8681 identified studies were included in the review, all of which included people with rheumatoid arthritis using various NSAIDs, including aspirin. There were no identified studies for other forms of inflammatory arthritis.For NSAIDs, 13 studies were included that used concurrent NSAIDs, of which nine studies examined unspecified NSAIDs. The mean number of participants was 150.4 (range 19 to 315), mean duration 2182.9 (range 183 to 5490) days, although the study duration was not always clearly defined, and the studies were mainly of low to moderate quality. Two of these studies reported no evidence for increased risk of methotrexate-induced pulmonary disease; one study assessed the effect of concurrent NSAIDs on renal function and found no adverse effect; one study identified no adverse effect on liver function; three studies demonstrated no increase in methotrexate withdrawal; and one study showed no increase in all adverse events, including major toxic reactions. However, transient thrombocytopenia was demonstrated in one study, specifically when NSAIDs were taken on the same week day as methotrexate. This study was a retrospective review that involved small numbers only and was of moderate quality; these finding have not been replicated since.Four studies looked at specific NSAIDs (etodolac, piroxicam, celecoxib and etoricoxib), with a mean number of participants of 25.8 (range 14 to 50) and mean study duration of 16.8 (range 14 to 23) days. These studies were mainly of moderate quality. The studies were primarily pharmacokinetic studies but also reported adverse events as secondary outcomes. There were no clinically significant adverse effects with concomitant piroxicam or etodolac; and only mild adverse events with celecoxib or etoricoxib, such as nausea and vomiting, and headaches.For aspirin, seven studies provided data on adverse events with the use of aspirin and methotrexate. These studies included a mean number of participants of 100 (range 11 to 232), had a mean duration of 1325 (range 8 to 2928) days and were mainly of low to moderate quality. Two of the studies reported no evidence for increased risk of methotrexate-induced pulmonary disease and two studies showed no increase in all adverse events including major toxic reactions; however, none of these studies specified the dose of aspirin that was used. One study demonstrated that concurrent aspirin adversely affected liver function at a mean dose of 6.84 tablets of aspirin per day, which is a possible daily dose of 2.1 g presuming that 300 mg aspirin tablets were given. A further study described a partially reversible decline in renal function with 2 g daily of aspirin. One study reported no increase in adverse events with 975 g aspirin daily, however the study duration was only one week.For paracetamol, no studies were identified for inclusion.

AUTHORS' CONCLUSIONS

In the management of rheumatoid arthritis, the concurrent use of NSAIDs with methotrexate appears to be safe provided appropriate monitoring is performed. The use of anti-inflammatory doses of aspirin should be avoided.